Why do tree leaves turn gold, orange and scarlet in the fall? “Chemistry of Changing Leaves” explains the role of pigment molecules, including chlorophyll, carotenoids, and anthocyanin. We also profile North Carolina State “green” chemist Elon Ison, who is designing catalysts to make safer, cleaner alternative fuels. Also in this collection: news stories from the archives of NBC News and Scientific American on leaf change and “green” fuels, plus a NOAA diagram on why seasons change, and charts and photographs for virtual leaf-peepers.

Why do tree leaves turn gold, orange and scarlet in the fall? “Chemistry of Changing Leaves” explains the role of pigment molecules, including chlorophyll, carotenoids, and anthocyanin. We also profile North Carolina State “green” chemist Elon Ison, who is designing catalysts to make safer, cleaner alternative fuels. Also in this collection: news stories from the archives of NBC News and Scientific American on leaf change and “green” fuels, plus a NOAA diagram on why seasons change, and charts and photographs for virtual leaf-peepers.